Special tool for measuring airplane wheel bearing clearance and measuring method

Abstract

The invention, which belongs to the technical field of aviation equipment, discloses a special tool for measuring a bearing gap of an airplane wheel and a measuring method thereof, comprising a pressing block, a straight rod, a weight and a base. The straight rod is fixed on the base, the airplane wheel penetrates through the straight rod and falls on the base, the weight of the weight is 73.5 N, the penetrating straight rod is pressed on a bearing on the upper side of the airplane wheel, the pressing block is inserted into the straight rod from the side face to press the weight, and the dial indicator is installed at the top end of the straight rod to measure the position change of the upper surface of the pressing block. During measurement, the height of the upper surface of the pressing block is measured when the bush is not installed, the height of the upper surface of the pressing block is measured again after the bush is installed, and the difference value between the two times is the bearing clearance. According to the invention, the stability and accuracy of the axial measurement of the airplane wheel bearing are realized through mechanical operation, the purpose of measuring the axial clearance through single operation by one person is realized, and the force application is uniform, so that the maintenance quality of an airplane is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of aviation equipment, and relates to a special tooling and measuring method for measuring the clearance of an aircraft wheel bearing. Background Technique

[0002] When overhauling a certain type of aircraft, it is necessary to measure the clearances of two bearings of the wheels on the front landing gear of the aircraft to determine whether the bushings installed between the two bearings meet the requirements. The process requirement is to measure the axial clearance of the bearing under the action of a 73.5 N force, and the bearing clearance should be (0.12 - 0.18) mm. The existing tooling applies force by manually holding a spring dynamometer with human hands to squeeze the bearing. When operating, the manual squeezing force applied by humans needs to be uniform and accurate. Since the wheel diameter is about φ230 mm and the mass is about 10 kg, a relatively large force is required. At the same time, when measuring, it is necessary to ensure the stability of the wheel. One person simply cannot operate, and at least 2 operators are required to cooperate. Therefore, there is an urgent need for a special tooling for measuring the axial clearance of wheel bearings. Summary of the Invention

[0003] In view of this, the present invention provides a special tooling and measuring method for measuring the clearance of an aircraft wheel bearing to realize the measurement of the clearance of the wheel bearing of this type of aircraft and ensure the quality and safety of aircraft overhaul.

[0004] The present invention adopts the following technical solutions:

[0005] A special tooling for measuring the clearance of an aircraft wheel bearing includes a positioning screw 1, a dial indicator base 2, a pressure block 3, a straight rod 4, weights 5, a base 6, a fixing nut 7, and a chassis 8.

[0006] The base 6 is a hollow cylinder with an open bottom. The outer diameter of its top is set according to the diameter of the wheel bearing. A threaded through-hole is made at the center of the top surface, and the outer circle of its bottom is fixedly connected to the annular chassis 8.

[0007] The diameter of the straight rod 4 is set according to the inner hole of the wheel bearing. A radial through-hole is made in its upper part. The through-hole is a vertically arranged long strip. An installation hole communicating with the strip through-hole is made at the center of the upper end surface of the straight rod 4. A threaded column with the same axis and a smaller diameter is provided at the lower end of the straight rod 4 for fastening connection with the threaded through-hole on the top surface of the base 6. And the lower end of the threaded column passes through the bottom of the threaded through-hole of the base 6, and a fixing nut 7 is screwed on the protruding part to strengthen the fastening of the straight rod 4 and the base 6 and improve stability. After the wheel bearing is inserted into the straight rod 4, it lands on the base 6.

[0008] The weight of the weight 5 is 73.5 N. It has a through hole in the center, and the diameter of the through hole is set according to the outer diameter of the straight rod 4. The weight 5 is inserted into the straight rod 4 and presses on the wheel bearing. After insertion, the upper end face of the weight 5 is located at the upper radial through hole of the straight rod 4. A pressing block 3 is inserted into the radial through hole to press the weight 5 tightly; to ensure that the force of the weight only acts on the wheel bearing, a convex platform is provided in the middle of the bottom surface of the weight 5, and the diameter of the convex platform is set according to the diameter of the wheel bearing.

[0009] The dial indicator base 2 is inserted into the mounting hole at the top of the straight rod 4 for the dial indicator to be inserted. Threaded holes are made on the side wall of the dial indicator base 2, and positioning screws 1 are installed in the threaded holes to fix the dial indicator. The measuring head of the dial indicator is attached to the top surface of the pressing block 3 for measuring the height change of the pressing block 3, thereby obtaining the bearing clearance.

[0010] A method for measuring the clearance of an aircraft wheel bearing includes the following steps:

[0011] Step 1, insert the wheel without the bushing installed into the straight rod 4 and place it on the base 6. Insert the weight 5 into the straight rod 4 and press it on the upper surface of the wheel bearing, and insert the pressing block 3 to press the weight 5 tightly.

[0012] Step 2, install a dial indicator in the dial indicator base 2 and insert it into the mounting hole at the top of the straight rod 4, so that the measuring head of the dial indicator is attached to the top surface of the pressing block 3 and zero the dial indicator.

[0013] Step 3, remove the dial indicator together with the dial indicator base 2, then remove the wheel, install a bushing between its two bearings, repeat Step 1, insert the wheel into the straight rod 4 again and install the weight 5 and the pressing block 3.

[0014] Step 4, insert the dial indicator base 2 with the dial indicator installed into the mounting hole at the top of the straight rod 4, so that the measuring head of the dial indicator is attached to the top surface of the pressing block 3. The reading of the dial indicator is the clearance between the two bearings. The bearing clearance should be (0.12 - 0.18) mm. Judge whether the measured value meets the requirements. If it does not meet the requirements, adjust the length of the bushing until it meets the requirements.

[0015] The beneficial effects of the present invention: The present invention realizes the stability and accuracy of the axial measurement of the aircraft wheel bearing through mechanical operation, realizes the purpose of measuring the axial clearance by a single person alone, and the force application is uniform, thus ensuring the aircraft maintenance quality. Description of the Drawings

[0016] Figure 1 It is the effect diagram of the use of the present invention.

[0017] Figure 2 It is the schematic diagram of the straight rod of the present invention.

[0018] Figure 3 It is the schematic diagram of the weight of the present invention.

[0019] Figure 4 Schematic diagram of the base of the present invention.

[0020] Figure 5 Schematic diagram of the measurement process of the present invention.

[0021] Among them, 1 - positioning screw; 2 - dial indicator base; 3 - pressure block; 4 - straight rod; 5 - weight; 6 - base; 7 - fixing nut; 8 - chassis; 9 - bushing. Specific embodiments

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following will describe in detail the specific embodiments of the present invention according to the technical solutions.

[0023] A special tool for measuring the clearance of an aircraft wheel bearing, as Figure 1 shown, includes a positioning screw 1, a dial indicator base 2, a pressure block 3, a straight rod 4, a weight 5, a base 6, a fixing nut 7, and a chassis 8.

[0024] As Figure 4 shown, the base 6 is a hollow cylinder with an open bottom end. Its top outer diameter is set according to the diameter of the wheel bearing. A threaded through hole is made in the center of the top surface. Its bottom outer circle is fixedly connected to the annular chassis 8. To reduce the processing difficulty, the base 6 and the chassis 8 are separately processed and then welded into one body to ensure that the bottom surface is horizontal.

[0025] As Figure 2 shown, the diameter of the straight rod 4 is set according to the inner hole of the wheel bearing. A radial through hole is made in its upper part. The through hole is a vertically arranged long strip. An installation hole communicating with the strip through hole is made in the center of the upper end surface of the straight rod 4. A coaxial and smaller-diameter threaded column is provided at the lower end of the straight rod 4 for fastening connection with the threaded through hole on the top surface of the base 6. And the lower end of the threaded column passes through the bottom of the threaded through hole of the base 6. A fixing nut 7 is screwed on the protruding part to strengthen the fastening of the straight rod 4 and the base 6 and improve the stability. After the wheel bearing is inserted into the straight rod 4, it lands on the base 6.

[0026] As Figure 3 shown, the weight 5 weighs 73.5 N. A through hole is made in its center. The diameter of the through hole is set according to the outer diameter of the straight rod 4. After the weight 5 is inserted into the straight rod 4, it presses on the wheel bearing for evenly applying force to the bearing. After insertion, the upper end surface of the weight 5 is located at the upper part of the radial through hole of the straight rod 4. A pressure block 3 is inserted into the radial through hole to press the weight 5; to ensure that the weight force only acts on the wheel bearing, a boss is provided in the middle of the bottom surface of the weight 5. The diameter of the boss is set according to the diameter of the wheel bearing. The size of the weight 5 is processed after calculation, and the weight is repeatedly measured after processing until it is ensured to be 73.5 N ± 1 N.

[0027] The described dial indicator base 2 is inserted into the mounting hole at the top of the straight rod 4 for the dial indicator to be inserted. A threaded hole is made on the side wall of the dial indicator base 2, and a positioning screw 1 is installed in the threaded hole to fix the dial indicator. The measuring head of the dial indicator is attached to the top surface of the pressure block 3 for measuring the height change of the pressure block 3.

[0028] A method for measuring the bearing clearance of an aircraft wheel includes the following steps:

[0029] Step 1: Pass the wheel without the installed bushing through the straight rod 4 and place it on the base 6. Pass the weight 5 through the straight rod 4 and press it on the upper surface of the wheel bearing. Insert the pressure block 3 to press the weight 5 tightly.

[0030] Step 2: Install a dial indicator in the dial indicator base 2 and insert it into the mounting hole at the top of the straight rod 4, making the measuring head of the dial indicator attach to the top surface of the pressure block 3 and zero the dial indicator.

[0031] Step 3: Remove the dial indicator together with the dial indicator base 2, then remove the wheel, install a bushing between its two bearings, repeat Step 1, pass the wheel through the straight rod 4 again and install the weight 5 and the pressure block 3, as Figure 5 .

[0032] Step 4: Insert the dial indicator base 2 with the installed dial indicator into the mounting hole at the top of the straight rod 4, making the measuring head of the dial indicator attach to the top surface of the pressure block 3. The reading of the dial indicator is the clearance between the two bearings. The bearing clearance should be (0.12 - 0.18) mm. Judge whether the measured value meets the requirements. If it does not meet the requirements, adjust the length of the bushing until it meets the requirements.

[0033] In summary, the above is only the preferred embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A special tooling for measuring the clearance of an aircraft wheel bearing, characterized in that It includes a briquette (3), a straight rod (4), weights (5), and a base (6). The base (6) is a hollow cylinder with an open bottom. Its outer diameter at the top is set according to the diameter of the wheel bearing, and a threaded through-hole is made at the center of the top surface. The diameter of the straight rod (4) is set according to the inner hole of the wheel bearing. Radial through-holes are made in its upper part. The through-holes are long strips arranged vertically. An installation hole communicating with the strip-shaped through-hole is made at the center of the upper end surface of the straight rod (4) for installing a dial indicator. A threaded post with the same axis and a smaller diameter is provided at the lower end of the straight rod (4) for firmly connecting with the threaded through-hole on the top surface of the base (6). After the wheel bearing is inserted into the straight rod (4), it is placed on the base (6). A through-hole is made at the center of the weight (5). The diameter of the through-hole is set according to the outer diameter of the straight rod (4). A boss is provided in the middle of the bottom surface of the weight (5). The diameter of the boss is set according to the diameter of the wheel bearing. After the weight (5) is inserted into the straight rod (4), it presses on the wheel bearing. After insertion, the upper end surface of the weight (5) is located at the upper part of the radial through-hole of the straight rod (4). A briquette (3) is inserted into the radial through-hole to press the weight (5). The measuring head of the dial indicator is attached to the top surface of the briquette (3) for measuring the height change of the briquette (3), and thus the bearing clearance can be obtained.

2. The special tooling for measuring the clearance of an aircraft wheel bearing according to claim 1, characterized in that The outer circle at the bottom of the base (6) is fixedly connected to an annular chassis (8).

3. The special tooling for measuring the clearance of an aircraft wheel bearing according to claim 1, characterized in that, The lower end of the threaded post of the straight rod (4) passes through the bottom of the threaded through-hole of the base (6), and a fixing nut (7) is screwed on the protruding part to improve stability.

4. A special tooling for measuring the clearance of an aircraft wheel bearing according to claim 1, characterized in that, The weight of the weight (5) is 73.5 N.

5. The special tooling for measuring the clearance of an aircraft wheel bearing according to claim 1, characterized in that It also includes a dial indicator base (2) inserted into the installation hole at the top of the straight rod (4) for the dial indicator to be inserted. A threaded hole is made on the side wall of the dial indicator base (2), and a positioning screw (1) is installed in the threaded hole to fix the dial indicator.

6. A method for measuring the clearance of an aircraft wheel bearing, which is implemented based on the special tooling for measuring the clearance of an aircraft wheel bearing described in any one of claims 1 to 5, characterized in that, It includes the following steps: Step 1: Pass the wheel without a bushing through the straight rod (4) and place it on the base (6). Pass the weight (5) through the straight rod (4) and press it on the upper surface of the wheel bearing. Insert the briquette (3) to press the weight (5). Step 2: Install the dial indicator in the installation hole at the top of the straight rod (4), make the measuring head of the dial indicator attach to the top surface of the briquette (3), and zero the dial indicator. Step 3: Remove the dial indicator, then remove the wheel, install a bushing between its two bearings, repeat Step 1, pass the wheel through the straight rod (4) again and install the weight (5) and the briquette (3). Step 4: Install the dial indicator in the installation hole at the top of the straight rod (4) again, and ensure that the installation positions of the dial indicator are the same for both times. Make the measuring head of the dial indicator attach to the top surface of the briquette (3). The reading of the dial indicator is the clearance between the two bearings. Judge whether the measured value meets the requirements. If it does not meet the requirements, adjust the length of the bushing until it meets the requirements.

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